DNA Replication Flashcards
What does DNA stand for?
Deoxyribonucleic acid
What does RNA do?
Transfers genetic information from DNA to the ribosomes.
Describe the structure of a nucleotide
Phosphate group, pentose sugar ( deoxyribose or ribose ), and a nitrogen containing organic base. (AT/AU, CG.)
What is the bond between bases?
Hydrogen bonds.
What is the bond that joins nucleotides?
Phosphodiester
What is two similarities between DNA and RNA
Helix of sugar phosphates
Cytosine and Guanine are complementary
Name 2 differences between DNA and RNA
•DNA has a double helix (two strands) but RNA has one.
•RNA has a Uracil base instead of Thymine in DNA.
•RNA is short, DNA long.
•RNA has no bases that are paired. DNA does.
What does A and T stand for?
Adenine
Thymine
What do C and G stand for?
Cytosine
Guanine
What is the bond between the sugar and the base in a nucleotide?
Glycosidic bond
What is DNA helicase?
The enzyme that breaks down the hydrogen bonds between the strands to separate them and so they can act as templates for for the new nucleotides.
What is DNA polymerase?
They attach new nucleotides to the strand for new sugar phosphate back bone to form with phosphodiester bonds between nucleotides. Catalyses condensation reactions between the nucleotides
Why does the enzyme DNA polymerase work in opposite directions
The DNA strands are anti-parallel so the enzyme’s active site is only complementary to the shape of the nucleotides in 1 direction, towards the 3 prime end. The shape of the nucleotides are different on each end of the strand.
What does ATP stand for?
Adenosine Triphosphate
What is ATP?
A store of energy. Energy released from respiration is used to make ATP.
Describe how ATP is created
ADP + Pi in a condensation reaction, catalysed by ATP synthase
What enzyme creates the bond in atp?
ATP synthase
What enzyme breaks the bond in ATP?
ATP hydrolase
How is ATP different from glycogen?
•ATP is an immediate source of energy, not a store.
•releases less energy (more manageable for cells so reactions can be more controlled)
•hydrolysis into ADP is a single reaction not a series of reactions.
•rapid condensation reactions, continuously reformed.
What is ATP made of?
Adenine, ribose sugar and three phosphate groups.
Why is DNA replication semi-conservative?
Each copy contains one original strand and one newly synthesised strand. The information from one half of the original DNA molecule is used
What is the function of ATP hydrolase?
Breaks down ATP into ADP and Pi and releases energy which can be used for muscle contraction.
Features of DNA that are important in semi-conservative replication of DNA.
•Double stranded so both can act as templates for new nucleotides
•system of complementary base pairing so new nucleotides can join to their complementary bases
•weak hydrogen bonds between bases for two strands to separate
